There are two FPMs in an MSF file, the idea being that for
incremental updates you can write to the alternate one and then
atomically swap them on commit. LLVM defaulted to using FPM1
on the first commit, but this differs from Microsoft's behavior
which is to default to using FPM2 on the first commit. To
eliminate some byte-level file differences, this patch changes
LLVM's default to also be FPM2.
Additionally, LLVM was trying to be "smart" about marking FPM
pages allocated. In addition to marking every page belonging
to the alternate FPM as unallocated, LLVM also marked pages at
the end of the main FPM which were not needed as unallocated.
In order to match the behavior of Microsoft-generated PDBs, we
now always mark every FPM block as allocated, regardless of
whether it is in the main FPM or the alt FPM, and regardless of
whether or not it describes blocks which are actually in the file.
This has the side benefit of simplifying our code.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@328812 91177308-0d34-0410-b5e6-96231b3b80d8
The PDB reserves certain blocks for the FPM that describe which
blocks in the file are allocated and which are free. We weren't
filling that out at all, and in some cases we were even stomping
it with incorrect data. This patch writes a correct FPM.
Differential Revision: https://reviews.llvm.org/D36235
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@309896 91177308-0d34-0410-b5e6-96231b3b80d8
When we create a PDB file using PDBFileBuilder, the information
in the superblock, such as the size of the resulting file, is not
available.
Previously, PDBFileBuilder::initialize took a superblock assuming
that all the members of the struct are correct. That is useful when
you want to restore the exact information from a YAML file, but
that's probably the only use case in which that is useful.
When we are creating a PDB file on the fly, we have to backfill the
members.
This patch redefines PDBFileBuilder::initialize to take only a
block size. Now all the other members are left as default values,
so that they'll be updated when commit() is called.
Differential Revision: https://reviews.llvm.org/D25108
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@282944 91177308-0d34-0410-b5e6-96231b3b80d8
Previously this change was submitted from a Windows machine, so
changes made to the case of filenames and directory names did
not survive the commit, and as a result the CMake source file
names and the on-disk file names did not match on case-sensitive
file systems.
I'm resubmitting this patch from a Linux system, which hopefully
allows the case changes to make it through unfettered.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@277213 91177308-0d34-0410-b5e6-96231b3b80d8
